Needle plate and sewing machine including same

Abstract

In a needle plate, a needle plate hole is configured to include a hole-side cutting side that cuts a cutting target object together with a blade portion, and a relief side that allows a cut portion of the cutting target object to escape. Specifically, the needle plate hole has the hole-side cutting side that shears the cutting target object together with a blade-side cutting side of the blade portion, and the relief side that forms a gap between the blade portion to be inserted and the relief side. In this manner, in the former stage of cutting processing, the cutting target object can be cut by the hole-side cutting side and the blade-side cutting side.

What is claimed is: 
     
       1. A cutwork mechanism of a sewing machine,
 the cutwork mechanism comprising: 
 a needle plate body provided below a needle bar that is moved up and down; and 
 a needle plate hole which is formed in the needle plate body, and into which a blade portion of a cutwork blade attached to a lower end portion of the needle bar is inserted, 
 wherein: 
 the needle plate hole includes a hole-side cutting side which cuts a cutting target object together with the blade portion, and a relief portion which allows the cutting target object that has been cut to escape; 
 the blade portion has a blade-side cutting side that cuts the cutting target object together with the hole-side cutting side; 
 the needle plate hole has a regular polygonal shape configured by a plurality of sides, one of the sides being formed to fit the blade-side cutting side; 
 the hole-side cutting side is configured by one side of the needle plate hole; 
 the relief portion is configured by remaining sides of the plurality of sides of the needle plate hole; and 
 the blade portion is rotated around an axis extending through a center of the regular polygon shape. 
 
     
     
       2. The cutwork mechanism according to  claim 1 ,
 wherein, when the blade portion is inserted into the needle plate hole, a gap through which the cutting target object is able to pass is formed by the cutwork blade and the relief portion. 
 
     
     
       3. The cutwork mechanism according to  claim 1 ,
 wherein 
 the blade-side cutting side is formed linearly along the hole-side cutting side when seen from an axial direction of the needle bar, and 
 the hole-side cutting side has a linear shape corresponding to the blade-side cutting side. 
 
     
     
       4. A sewing machine comprising a cutwork mechanism,
 wherein: 
 the cutwork mechanism includes 
 a needle plate body provided below a needle bar that is moved up and down; and 
 a needle plate hole which is formed in the needle plate body, and into which a blade portion of a cutwork blade attached to a lower end portion of the needle bar is inserted, and 
 wherein: 
 the needle plate hole includes a hole-side cutting side which cuts a cutting target object together with the blade portion, and a relief portion which allows the cutting target object that has been cut to escape; 
 the blade portion has a blade-side cutting side that cuts the cutting target object together with the hole-side cutting side; 
 the needle plate hole has a regular polygonal shape configured by a plurality of sides, one of the sides being formed to fit the blade-side cutting side; 
 the hole-side cutting side is configured by one side of the needle plate hole; 
 the relief portion is configured by remaining sides of the plurality of sides of the needle plate hole; and 
 
       the blade portion is rotated around an axis extending through a center of the regular polygon shape.